The breakdown and synthesis of carbohydrates, proteins, and lipids connect with the pathways of glucose catabolism. The simple sugars are galactose, fructose, glycogen, and pentose. These are catabolized during glycolysis. The amino acids from proteins connect with glucose catabolism through pyruvate, acetyl CoA, and components of the citric acid cycle. Cholesterol synthesis starts with acetyl groups, and the components of triglycerides come from glycerol-3-phosphate from glycolysis and acetyl groups produced in the mitochondria from pyruvate.

1. Sweta Ghosh
West Bengal State University
Food & Nutrition

2.  Introduction
 Carbohydrate
 Carbohydrate metabolism
 Protein
 Protein metabolism
 Fat
 Fat metabolism
 Inter conversion between 3 principal components
 Relation between the metabolism of protein , carbohydrates and
fats
 Carbohydrate & lipid metabolism
 Relationship between lipid and carbohydrate metabolism
 Carbohydrate & protein metabolism
 Relationship between protein and carbohydrate metabolism
 Summery
 Conclusion
 Reference

3.  Carbohydrates, protein and fat are macronutrients.
 In the human body metabolism is the oxidization of
carbohydrates, protein and fat to give CO2, H2O and
energy.
 Cellular metabolism describes the process by which
the products of digestion are chemically modified to
yield usable energy.

4.  Carbohydrates are sugar.
 It provide energy for daily activity.
 Provide to allow proper organ
function.
 Provide to the energy of life.
 Intermediate energy in the form
of GLUCOSE.
 Store energy in the form of
GLYCOGEN.

6.  Proteins are a sequences of amino acids.
 Proteins are molecular machines , building blocks ,and arms
of a living cell.
 Protein is the major source
of energy .
 Protein produces
enzymes that increase the
rate of chemical reactions
in the body
 Protein is involved in the
creation of some
hormones.

8.  Fats are organic compounds composed of carbon , hydrogen,
and oxygen, content and are usually flammable and slippery.
 Fat produce heat and energy.
 Fats insulate the body with a layer of adipose tissue.
 Fat protect delicate
organs ( e.g. Kidneys ).
 There are a source
of fat soluble vitamins
– A,D,E and k.

10.  Conversion of carbohydrates into fats and fats into
carbohydrates.
 Conversion of carbohydrates into proteins and proteins into
carbohydrates.
 Conversion of proteins into fats and fats into proteins.

12.  The fasting state
◦ Amino acids , glycerol, lactate used for gluconeogenesis
◦ Ketone formation
 The starvation state
◦ Fatty acids used to greater extent
◦ Glycerol major glucose source
◦ Ketosis after oxaloacetate depletion

13.  Acetyl CoA is the link between lipid and carbohydrate
metabolism pathways.
 Glucose , glycerol and fatty acids all degrade into acetyl CoA
 Biosynthesis of fatty acids , ketone bodies & cholesterol all
use acetyl CoA.

14.  The metabolism of fatty acids and that of carbohydrates and
protein are intimately related.
 The constituents are in a constant state of flux. Even the
structural proteins, carbohydrates and storage lipids are
constantly broken down and rebuilt.
 The status of a particular animal is the net result between
the rates of synthesis and of breakdown of its body
constituents.

15.  Glycerol is the only component of lipids that is involved in
the synthesis of carbohydrates.
 On the other hand , lipids can be formed from carbohydrate
in many ways .
 Indeed , the metabolism of lipids, carbohydrates and
proteins is metabolically dynamic.

16.  The breakdown and synthesis of carbohydrates, proteins,
and lipids connect with the pathways of glucose catabolism.
 The simple sugars are galactose, fructose, glycogen, and
pentose. These are catabolized during glycolysis.
 The amino acids from proteins connect with glucose
catabolism through pyruvate, acetyl CoA, and components
of the citric acid cycle.
 Cholesterol synthesis starts with acetyl groups, and the
components of triglycerides come from glycerol-3-
phosphate from glycolysis and acetyl groups produced in the
mitochondria from pyruvate.

17.  In the human body metabolism is the oxidization of
carbohydrates, protein and fat to give CO2, H2O and energy.
 The metabolism of lipids, carbohydrates and proteins is
metabolically dynamic.
 So, the metabolism of fatty acids and that of carbohydrates
and protein are intimately related.

18.  Integration of metabolism – Ashok Katta
 www.ncbi.nlm.nih.gov
 www.gasexchange.com
 Wikipedia
 Proteins – Deepika
 Fat – Dr. Shailendra Meena